Do Aus have a mid-on and two short mid-wickets? One a bit forward and one a bit backward when Siddle is bowling to Root? Why is that?

He's attacking the stumps, probably trying to get him to play square and bring lbw into play. There's also been a few hold up in the deck, and with the way Root stays on the crease he's a chance not to get to one and chip it to those blokes in close